Sen. Ted Cruz says GOP presidential rival Donald Trump won't be able to mount a third-party White House bid if he loses the party's nomination — because of a number of states' "sore-loser" laws would block his path.

In an radio interview with Wisconsin radio host Charlie Sykes on Thursday, the Texas lawmaker conceded Trump would likely "throw a fit" if he doesn't win enough delegates to secure the nomination outright, or loses a contested GOP convention in Cleveland in July, Politico reports.

"You know, Donald doesn't handle losing well," Cruz said, Politico reports. "So there is a risk if he loses — and I believe we're gonna win this nomination and win 1,237 delegates — there's a risk that Donald takes his marbles and goes home and throws a fit. I hope he doesn't, but it's not complicated to see that's a real risk."

Still, a third-party run won't work anyhow, he said.

"Quite a few states across the country have what are called sore-loser laws, that once you run as a Republican and lose, you don't get to then turn around and file on the ballot as an independent, so that will not be an option available to him," Cruz said, Politico reports.

Trump holds a 273-delegate advantage over Cruz, Politico notes.

Cruz also insisted he's the candidate tha'll be able to unite the party if he was the GOP standard-bearer, pointing to key endorsements he's already picked up, including that of Wisconsin Gov. Scott Walker.

"I think that is a powerful demonstration of unity of the party coming together, and we're gonna continue working to unify the party, and I think even if Donald throws a tantrum and goes home, I think a great many of his supporters, if we have a fair battle at the ballot box and then at the convention with the delegates who are elected by the people voting, I think a great many of those voters and supporters will remain energized," Cruz said, Politico reports.

"I've got a lot of support in the same demographics he does. And we're gonna have to work to do that. That's our challenge in front of us."

Sen. Ted Cruz says GOP presidential rival Donald Trump won't be able to mount a third-party White House bid if he loses the party's nomination - because of a number of states' "sore-loser" laws would block his path.